Climate stories continue to float across my viewing zone, especially lately in the New Scientist, which for us is loo reading. NS articles are usually pay-walled, so I’ll try catch up a bit.
There are lots of tipping points in ecosystems and the climate, and many are interconnected. That means the massive changes we are wreaking will have many unexpected consequences.
“The world is a much more surprising place then generally assumed,” says Garry Peterson of the Stockholm Resilience Centre in Sweden. As an example, in 2016 the retreat of a glacier in Canada led to a river changing direction.
Peterson’s team has analysed 300 ecosystems with potential tipping points or regime changes. For instance, as rainfall increases grasslands can suddenly turn into forests, and vice versa.
The study suggests that almost half of them are linked.
For example, more extreme rainfall can greatly increase soil erosion, which then carries more phosphorus into rivers, lakes and the sea. This can trigger algal blooms and red tides, and lead to bigger “dead zones”, which then cause further knock-on effects.
The team’s work shows that:
- crossing one tipping point increases the risk of crossing another and so triggering a whole cascade of effects. And we may not even recognise the danger until it is too late, Peterson says.
A big one is Antarctica, which they say is past its tipping point, linking to another article which says:
- It’s too late to stop the seas rising at least 5 metres and only fast, drastic action will avert a 20-metre rise, New Scientist calculates based on recent studies.
We just don’t know whether it will take centuries or millennia.
That article was dated 10 June, 2015 and relies on studies published in 2013.
When Terry Hughes and colleagues at James Cook University flew over the reef to visually assess the level of coral bleaching they found that in 2017 less bleaching occurred than in 2016 even though the reef was exposed to more extreme temperatures in 2017:
- It took about twice the amount of heat stress – for example the same elevated temperature but for twice as long – to cause the same level of damage in the second year as in the first, they calculated (Nature Climate Change, doi.org/cxsw).
One reason may be that corals are gradually adapting to the warmer climate by switching on different genes or other biochemical mechanisms, says Hughes, but this needs to be experimentally verified.
Another reason may be that the corals that survived the first heatwave were tougher species, meaning they were better able to cope with the second assault, says Hughes. His team previously found that dome-shaped corals were more likely to survive after the 2016 heatwave than branched and table corals.
The thinking is that there will likely be a reef in 50 years time, but it will be very different.
- A giant meteorite crater that has turned up under the Greenland ice sheet may hold clues to a mini ice age some 13,000 years ago.
An international team found the 30-kilometre-wide feature using NASA radar data. It would have been made by a meteorite about 1 kilometre across.
A river draining from under the ice covering the crater is washing out sediment particles with a telltale internal structure that results from a brief shock wave. “They’re absolutely characteristic of impact,” says team member Iain McDonald at Cardiff University, UK.
It’s under the ice, so they can’t actually date it. While it could be up to 3 million years old it would make a neat fit with the sudden cooling event known as the Younger Dryas, a sudden cooling event from about 12,900 BP to about 12,700.
From an article in The Independent:
That’s bigger than Paris.
The Union of Concerned Scientists (UCS) has decided to drop its long-standing opposition to nuclear power. Their report is here. Other environmentalists should too, says Mark Lynas.
The UCS is not pushing for new nuclear, rather concerned that old ones are likely to be shut down in the US, undercut by cheap fossil fuels, especially gas from fracking. They point to Germany, where coal is lingering longer because Merkel made a (dumb) decision to shut down nukes after Fukushima under political pressure from greenies and The Green Party.
This plane uses no fuel at all:
Instead of propellers or jet engines, the plane uses electrodes on its wings to produce ions that push against the surrounding air. The team claims the plane is quieter and cleaner than any other powered aircraft.
Electrodes are used to create an electric discharge that produces electrically charged atoms or molecules in the air. An electric field then accelerates these ions towards the back of the plane. Collisions with air molecules produce a thrust force in the opposite direction, pushing the plane forwards.
The plane produces more thrust per unit of power than a standard jet engine. But before you get too excited, it has only flown for 12 seconds, the same as the Wright Bros managed first up, managing 55 metres inside a sports hall. The plane flew at 5 metres per second compared to the 200 metres per second or more of a modern jetliner.
The plane was remote-controlled and weighed only 2.45 kg. They reckon the may have something useful in about 30 years.
Aviation generates more than 2 per cent of CO2 globally, with emissions set to double before 2050. Most countries are doing nothing about it, as aviation emissions are excluded from UN climate agreements. EU nations are an exception, as aviation fuel is subject to a carbon tax as part of a carbon trading scheme.
However, the EU carbon tax is not very effective.
In 2016, industry body the International Civil Aviation Organisation (ICAO) finally came up with up with its own plan. Rather than limit future emissions, however, the proposed Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), involves offsetting them …
- offsetting is ineffective. A 2017 EU report concluded that 85 per cent of UN schemes had not delivered the promised reductions.
The EU can only control what happens within their borders. They want the 150 megatonnes of CO2 produced in their patch to reduce to 110 by 2030. The ICAO approach would see them increase to 210.
So the matter is currently unresolved. Meanwhile Indonesia plans to make jet fuel out of palm oil, which is just disastrous, especially for orangutans.